Electromagnetic Metamaterials for Controlling Absorption and Thermal Emission

Abstract

Metamaterials, which derive their optical properties from subwavelength structures, have emerged in recent years as a promising way to tune refractive index and achieve optical properties not present in natural materials. These materials have been proposed for exciting applications including optical cloaking, super-resolution imaging, and ultra-thin optics; however, realization of these applications has been hindered by parasitic absorption loss. While much effort has been directed toward mitigating this loss, a new class of metamaterial designs has been developed to harness the loss and create materials with enhanced absorption and thermal emission properties. Despite promising initial results, the area is still in its infancy and the functionality of current metamaterial designs remains quite limited. In this dissertation, I study metamaterial architectures for enhanced absorption and thermal emission with a focus on improving material functionality to solve practical engineering challenges. Specifically, I develop metamaterial designs that achieve selective thermal emission at high temperatures for thermophotovoltaic energy conversion, dynamic thermal emission for infrared signature control, and reconfigurable visible light absorption for dynamic color control.